CHARACTERISTIC CHROMOSOMAL FRAGILITY OF HUMAN EMBRYONIC-CELLS EXPOSEDIN-VITRO TO APHIDICOLIN

The frequency and distribution of aphidicolin (APC)-induced common fra gile sites (cfs) were analyzed in human embryonic cells of different o rigins. Embryonic lung fibroblasts (MRC-5), amniocytes (AMNIO) and emb ryonic retina cells (HERO790) are as sensitive to the APC-induced clas togenic effect as peripheral lymphocytes, whereas embryonic kidney cel ls (HEK) seem more resistant to the induction of chromosomal gaps and breaks by the drug. Analysis of the distribution of fragile sites conf irmed that the expression of specific APC-induced cfs varies in differ ent cells and that the embryonic cell strains show a greater similarit y among themselves than to lymphocytes. In addition, HEK, MRC-5, HERO7 90 and AMNIO cells show specific APC induction of the cfs at the 1p31. 2 chromosomal band, which seems to be a distinctive feature of the emb ryonic stage of cells.